gdbm: fixes build for gettext 1.9

the package fails to build on SDK builder2

Signed-off-by: John Crispin <blogic@openwrt.org>

libs/gdbm/Makefile

@@ -19,7 +19,7 @@ PKG_LICENSE:=GPL-3.0+
 PKG_LICENSE_FILES:=COPYING
 PKG_MAINTAINER:=Marcel Denia <naoir@gmx.net>
 
-PKG_FIXUP:=autoreconf
+PKG_FIXUP:=autoreconf gettext-version
 PKG_REMOVE_FILES:=Makefile compat/Makefile doc/Makefile export/Makefile src/Makefile tests/Makefile
 PKG_BUILD_PARALLEL:=0